We have successfully grown normal and abnormal human thyroid cells in cell culture. We propose to study the cultural and radiobiological characteristics of these cultures utilizing cell growth and histology, serial photomicroscopy, iodokinetic studies with added radioiodine with chromatography of secreted products and direct assay for thyroid hormones. The effects of drugs and internally and externally administered radiation will be evaluated. The elaboration of specific markers of tumor growth will be examined by radioimmunoassay techniques developed in this laboratory. The growth of the tumor specimen in cell culture will be compared with the clinical course of the patient in an effort to develop a means of predicting the clinical outcome of the patient's thyroid cancer.